docs: add usage example

Signed-off-by: Daniel Bluhm <[email protected]>

README.md

@@ -1,9 +1,46 @@
 # did-peer-2
 
+[![pypi release](https://img.shields.io/pypi/v/did-peer-2)](https://pypi.org/project/did-peer-2/)
+
 A minimal did:peer:2 (and 3) library.
 
 did:peer:2 has (or will soon be) superseded by [did:peer:4](https://github.com/dbluhm/did-peer-4). Even so, we anticipate did:peer:2 being around for at least a while longer. This library is built against the most recent version of the did:peer:2 spec.
 
+## Install
+
+```sh
+pip install did-peer-2
+```
+
+## Usage
+
+```python
+>>> from did_peer_2 import generate, KeySpec, resolve, peer2to3
+>>> keys = [
+...     KeySpec.verification("z6Mkj3PUd1WjvaDhNZhhhXQdz5UnZXmS7ehtx8bsPpD47kKc"),
+...     KeySpec.encryption("z6LSg8zQom395jKLrGiBNruB9MM6V8PWuf2FpEy4uRFiqQBR")
+... ]
+>>> services = [
+...     {
+...         "type": "DIDCommMessaging",
+...         "serviceEndpoint": {
+...             "uri": "http://example.com/didcomm",
+...             "accept": ["didcomm/v2"],
+...             "routingKeys": ["did:example:123456789abcdefghi#key-1"],
+...         },
+...     },
+... ]
+>>> did = generate(keys, services)
+>>> print(did)
+did:peer:2.Vz6Mkj3PUd1WjvaDhNZhhhXQdz5UnZXmS7ehtx8bsPpD47kKc.Ez6LSg8zQom395jKLrGiBNruB9MM6V8PWuf2FpEy4uRFiqQBR.SeyJ0IjoiZG0iLCJzIjp7InVyaSI6Imh0dHA6Ly9leGFtcGxlLmNvbS9kaWRjb21tIiwiYSI6WyJkaWRjb21tL3YyIl0sInIiOlsiZGlkOmV4YW1wbGU6MTIzNDU2Nzg5YWJjZGVmZ2hpI2tleS0xIl19fQ
+>>> resolved = resolve(did)
+>>> assert isinstance(resolved, dict)
+>>> did3 = peer2to3(did)
+>>> print(did3)
+did:peer:3zQmbRvRJgKBuubq8T9VBjrDPTmjb2Ed91f89ekW4gr6aZxa
+
+```
+
 ## DID Peer 2 Specification
 
 If `numalgo` == `2`, the generation mode is similar to Method 0 (and therefore also did:key) with the ability to specify additional keys in the generated DID Document. This method is necessary when both an encryption key and a signing key are required. This method also enables including services in the generated DID Document.

pyproject.toml

@@ -7,6 +7,7 @@ authors = [
 ]
 dependencies = [
     "base58>=2.1.1",
+    "pytest-ruff>=0.1.1",
 ]
 requires-python = ">=3.9"
 readme = "README.md"
@@ -23,3 +24,21 @@ dev = [
     "ruff>=0.1.0",
     "pre-commit>=3.5.0",
 ]
+
+[tool.pytest.ini_options]
+addopts = "--doctest-glob README.md --ruff"
+
+[tool.ruff]
+select = ["E", "F", "C", "D"]
+
+ignore = [
+    # Google Python Doc Style
+    "D203", "D204", "D213", "D215", "D400", "D401", "D404", "D406", "D407",
+    "D408", "D409", "D413",
+    "D202", # Allow blank line after docstring
+]
+
+line-length = 90
+
+[tool.ruff.per-file-ignores]
+"**/{tests}/*" = ["F841", "D", "E501"]